Origin: A naturally occurring chemical in the body.

Claims: Treats pain, stiffness and joint swelling; improves mobility; rebuilds cartilage and eases symptoms of osteoarthritis (OA), fibromyalgia, bursitis, tendinitis, chronic low back pain and depression.

What we know: SAM-e is an effective anti-inflammatory and analgesic for people with OA. Results may be felt in just one week but could take more than a month. SAM-e works closely with vitamins B-12, B-6 and folate, so it is important to get enough of the B vitamins when taking this supplement.

Studies: Over the last two decades, multiple clinical trials involving thousands of people have shown SAM-e to improve joint health and help with the symptoms of OA.

A 2002 analysis of 14 SAM-e studies showed it is effective for reducing pain and improving mobility in people with OA.

A 2004 University of California, Irvine study found SAM-e equal to the prescription drug celecoxib (Celebrex) and a 2009 study found it comparable to the NSAID nabumetone.

Fibromyalgia findings have been mixed, but in two European trials (where it is sold as a drug, not a supplement), SAM-e improved symptoms better than placebo.

Extensive research has also found SAM-e effective for depression. In a 2010 Massachusetts General Hospital study, SAM-e combined with antidepressants significantly increased remission rates in patients with major depression who failed conventional therapy.

Dosage: Capsules (preferably in blister pack): 600 to 1,200 mg daily in three divided doses for OA; 200 to 800 mg twice daily for fibromyalgia; 800 to 1,600 mg twice daily for depression. Because of possible interactions, SAM-e should not be taken without doctor’s supervision.

 High doses of SAM-e can cause flatulence, vomiting, diarrhea, headache and nausea. SAM-e may interact with antidepressant medications and should be avoided if you have bipolar disorder or are taking monoamine oxidase inhibitors (MAOIs). It may also worsen Parkinson’s disease.